Electronic equipment, such as computers, facsimile machines and copiers, often are secured against unauthorized use by requiring a mechanical key for operation thereof. The key interfits with a key receptacle provided in the equipment, and movement of the receptable in turn controls an electrical switch that enables or disables the equipment depending on the position of the key.
Another level of security applied to such equipment is carried out by an identification card containing identification data encoded on a magnetic or optical stripe thereon, stored in an integrated circuit "chip" in the card, formed on embossments of the card, or a combination thereof. In some equipment, therefore, the manufacturer of the equipment must provide, and the user must carry, both a mechanical key and identification card, to operate the equipment.
The cost of providing an integrated circuit within a conventional credit card for this purpose is high, bearing in mind that the thickness of the card is, by standard, 30 mils. However, an integrated circuit for this purpose is necessary to process identification data stored therein, together with keyboard entered data, to determine whether the user is authorized to operate the equipment. The integrated circuit additionally carries out data logging and reporting.
For example, in U.S. patent application Ser. No. 236,614, of Benton et al., filed on Aug. 23, 1988 and assigned to the assignee of this invention (Benton I), an apparatus for carrying out financial transactions at a common site or at remote sites via a facsimile machine, uses, in one embodiment thereof, a key containing an integrated circuit "chip" for turning on the facsimile machine and storing transaction data as well as a facsimile signature of the owner. As disclosed in another application of Benton et al., (Benton II) Ser. No. 236,614, filed on Aug. 23, 1988, a particular key may be retained by a cord to an identification card containing information corresponding to information stored in the chip.
Although the "keys" disclosed in the Benton et al. applications are satisfactory, the keys are relatively expensive to produce. For example, the integrated circuit in Benton II must be packaged in a relatively thin (thin enough to interfit with a key receptacle) carrier, and formed with "teeth" having a predetermined orientation on the carrier. Wiring must be routed from the integrated circuit at one end of the carrier to electrical contacts on the teeth in the region of the other end. This routing of the wiring is difficult to carry out reliably since multiple wires must traverse a relatively narrow shank portion of the key.